1. Heat the oil in a heavy kettle and saute the onion until tender but not browned. Add tomatoes, pumpkin, broth, and salt and pepper to taste. Bring to a boil, cover, and simmer for 30 minutes, or until the pumpkin is tender.
2. Puree in the container of an electric blender or a food processor and return to the kettle. Stir in the cream and reheat.